Using goodrx coupons for controlled substances?

So....... I'm at war with my pharmacy. take a controlled substance med. because medicare part D coverage stinks, for years i have gotten 90 day refilled of my med using a GoodRX coupon. never any trouble. NOW, they are insisting that not only can I not use the coupon, i can't get a 90 day refill.

They said if you have medicare part D it is ILLEGAL not to use it, if you have it, and use a coupon instead, and the part D will only pay for 30 days at a time. They said this is a "new law" that went into effect for controlled substances.

I can't find ANY reference to any such new law online. Has anyone else encountered this and heard of this? Every time i pick up a controlled substance prescription they swipe my ID through a state database to make sure i'm not picking it up from multiple places with multiple prescriptions. THAT has always been how they ensure i'm not getting more than the quantity allowed to me. So WHY does it make ANY difference HOW I pay for it? The goal of controlled substance laws is to stop pill seeking which is done by limiting the quantity you can buy. Controlling HOW you pay for it means NOTHING.

WTF??????????